Compressive strength of masonry

砌体结构可以通过压缩、拉伸和剪切来加载。特别是在受压情况下，作为砌体单元和砂浆的复合材料，砌体结构更是显示出了它的能力。对砌体抗压强度的预测通常是通过经验或通过适当的力学模型进行的。由于砌体单元的相关参数(几何形状、孔洞含量、材料)、砂浆性能(密度、泊松比、强度)以及这些单元的吸水特性的影响差异很大，因此只有在个别情况下才可能进行准确的预测。由于影响的主要参数很多，形成了一个参数空间，仅靠实验研究是不能系统覆盖的。然而，在本研究项目的范围内，将进行足够数量的试验，以开发和验证预测砌体抗压强度的模型。为了能够经济地捕捉到其他单元-迫击炮组合，实验研究得到了有限元模型的支持。通过这项工作，将开发一个工程模型，在初始裂纹形成之前，该模型基于希尔斯多夫的断裂模型，并应扩展到包括直到抗压强度的部分非线性。最后，研究项目将产生一个新的概念来计算砌体抗压强度，从而可以更真实、更经济地评估受压荷载下的承载能力。

Masonry constructions can be loaded by compression, tension and shear. In particular in case of compression load, as a composite material of masonry unit and mortar, masonry shows its capability. The prediction of the masonry compressive strength is usually carried out empirically or by means of appropriate mechanical models. Because of the widely varying relevant parameters of masonry units (geometry, hole content, material), mortar properties (density, Poisson's ratio, strength) and the influence of the water absorbing characteristics of the units, a precise prediction is only possible in individual cases. In consequence of the large number of main influencing parameters, a parameter space is spanned, which can not be systematically covered only by experimental studies. Within the scope of this research project, however, a sufficient number of experiments is to be conducted in order to develop and to vaildate a model to predict the compressive strength of masonry. In order to be able to capture other unit-mortar combinations economically, the experimental investigations are supported by FE-modeling. With this work, an engineering model shall be developed, which, until the initial crack formation, is based on the fracture model of Hilsdorf and shall be expanded to include a proportion of non-linearity up to the compressive strength. In the end, the research project shall result in a new concept to calculate the masonry compressive strength, which allows a much more realistic and also more economic assessment of the bearing capacity under compressive load.